David,
I have a different tack on this than Andre.
I believe the X5000 port of OS4 is close to ready for release.
That would be one reason for shifting focus to the Tabor port.
And, releasing the X5000 before Tabor also makes sense.
As it would be the only A-eon system available it might help sales.

I think when benchmarks comparing the X5000 to Tabor are made, people are in for a rude awakening.
Sure, Tabor will be cheaper, but its performance is not likely to be much higher than a SAM460.